Language /
When to use: Znać/Wiedzieć & lub/albo [23]
Basically the difference is less semantic and more grammatical than similar pairs in other languages.
znać takes a nominal object (noun or pronoun)
znam to miasto (I know that city)
znam odpowiedzieć (I know the answer)
Znam go (I know him)
wiedzieć takes a sentential object (introduced by że)
wiem, że nie masz czasu (I know you don't have time)
wiem, że mieli przyjść (I know they were supposed to come)
or no object but a prepositional phrase
wiem o tym (I know (about it))
also wiedzieć can be followed by an infinitive clause with an embedded question marker (kto, co, jak, gdzie etc)
wiem co robić (I know what to do)
wiem jak to robić (I know how to do that)
but it can't be followed by a bare infinitive or infinitive clause, then it's replaced by umieć
*wiem robić (*used by linguists to mark incorrect usage)
umiem to robić (I know (how) to do that)
umiem pływać (I know how to swim)
compare:
nie znam odpowiedzi (I don't know the answer)
nie wiem co odpowiedzieć (I don't know what/how to answer)
nie umiem odpowiedzieć (I don't know how to answer)